HYPERFINE STRUCTURES OF THE TRIPLET-STATES OF (NARB)-NA-23-RB-85

The sub-Doppler high resolution excitation spectrum of NaRb was measured by selectively monitoring the fluorescence intensity from perturbed levels to the (1)3SIGMA+ lower state. Many transitions were observed to the (2)3SIGMA+ state perturbed by B1PI. Energy shifts of the perturbed levels were analyzed and the spin-orbit coupling constant between the (2)3SIGMA+ and B1PI states was determined, together with molecular constants of each state. Fully resolved hyperfine splittings, induced by the coupling of electron spin with both Na-23 and Rb-85 nuclear spins, were observed in the transitions. By analysis of the observed splittings, the mechanism of perturbation was confirmed as due to Fermi contact interaction and hyperfine constants of the Na-23 Rb-85 (2)3SIGMA+ state were determined. The ratio of electron spin densities at Na-23 and Rb-85 in the (2)3SIGMA+ state is estimated to be 0.84:0.16.